Web-like continuous textile structure



June 25, 1963 B. ROMANIN 3,095,338

WEB-LIKE CONTINUOUS TEXTILE STRUCTURE Filed Jan. 19, 1959 2 Sheets-Sheet1 FIG. IA T ===J x INVENTOR BRUNO ROMANIN ATTORNEYS June 25, 1963 B.ROMANIN 3,095,338

WEB-LIKE CONTINUOUS TEXTILE STRUCTURE Filed Jan. 19, 1959 2 Sheets-Sheet2 F|G.3 FIG.4

i m a INVENTOR BRUNO ROMANIN ATTORNEYS United States Patent 3,095,338WEB-LIKE CONTINUOUS TEXTILE STRUCTURE Bruno Romania, 3 Via ViucenzoMonti, Milan, Italy Fiied Jan. 19, 1959, Ser. No. 787,571 Claimspriority, application Italy Jan. 25, 1958 1 Claim. (Cl. 154-46) Theobject of the present invention is a new textile structure and a processfor manufacturing the same.

It is known that all textile fabrics comprise two sets of textile yarns,that is, the warp and the weft, which are woven together in a knownmanner by the usual looms.

Some uses, particularly industrial ones, require fabrics that can bemass-produced at a high speed and at a low cost.

The ordinary looms do not match these requirements, because, with rareexceptions, the traditional weaving of fabrics demands certainpreparatory operations on the yarns, such as for instance, preparationof the warp and spooling of the weft. Besides, looms always produce at alow speed because of the complicated motions required by ordinaryweaving.

Attempts have been made to substitute for the ordinary Woven fabrics forcertain purposes, the so called non-woven fabrics consisting of shortfibres which are arranged in a layer and are bonded by bondingsubstances to form a sheet but the products thus obtained have a limitedrange of applications, and are defective as to flexibility and strength,inasmuch as their mechanical characteristics, owing to the fact that thetextile material incorporated therein is discontinuous, dependessentially on the bonding material.

It is an object of the present invention to provide a new textilematerial consisting of continuous filaments or yarns which are notwoven, but are arranged in a plurality of planes, in part with arectilinear and in part with an undulated lay-out, said filaments oryarns suitably crossing and being adhesively connected to one another,so as to develop a tensional resistance, both in the longitudinal andthe transversal directions. Said textile material may constitute afinished or an intermediate product, and may be used alone, orimpregnated or associated with different fiuid or sheet materials, andmay be subjected to thermal and mechanical treatments, but all theoperations pertaining to the utilization of the said material are not apart of the invention and may be accomplished by methods and means knownin the art.

The process which is an object of this invention is characterized inthat the filaments or yarns are arranged in the desired straight andundulating paths in mutual crossing relation and are set in theirrespective configurations and mutual positioned relationship.

More particularly, it is characterized in that a plurality of sets ofyarns are continuously advanced in one direction, that concurrentlythere is imparted to a part of said sets of yarns an alternatingrectilinear motion in a direction substantially perpendicular to saidadvancing direction and in one or more planes fixed in space, that apressure is applied to all sets of yarns along a line fixed in space,substantially perpendicular to the aforementioned advancing direction,and displaced forwards in the aforementioned advancing direction withrespect to the aforesaid fixed plane or planes, and that concurrentlywith the application of pressure or successively, the sets of yarns towhich the aforementioned motions have been imparted, are set in theirresulting undulated paths and positioned relationship with one anotherand with the other yarns. Said paths are substantially sinusoidal. Theirshape and amplitude depend on the amplitude and speed of the alternativemotion and of the advancing 3,095,338 Patented June 25, 1963 motion.Pressure, heat, or adhesives, separately or jointly, ma be used to setthe yarns in their paths.

Preferably, the yarns are advanced by the same means which applypressure to the yarns. To that end, the yarns are gripped between twosurfaces tangent to one another, for example cylindrical or partlycylindrical and partly plane surfaces, which surfaces at the point atwhich they are tangent, move in the direction and with the speedrequired to advance the yarns.

Yarns of any nature are suitable for carrying out the invention, forinstance: cotton, waste silk, flax, jute, wool and other natural shortfibres; artificial and synthetic short fibres, such as spun viscose,spun acetate, polyamide, polyester, acryl, polyvinyl alcohol, polyvinylchloride and vinyl copolymer fibres, and olefinic fibres, such aspolyethylene and polypropylene; natural continuous filaments andfilament yarns, such as silk, artificial continuous filaments andfilament yarns, such as viscose rayon and cellulose acetate, andsynthetic continuous filaments and filament yarns of the same classes asthe synthetic fibres above listed; and inorganic yarns, such as glassyarns.

Whenever adhesive are required, any known adhesive may be employed, suchas for instance rubber latex adhesive; epoxide polyester resins andvinyl resins; natural gums and glues both vegetable and animal, and soon.

The invention will be better understood from the description of thefollowing embodiments, with reference to the appended drawings, wherein:

FIGURES 1 and 1 which integrate each other, diagrammatically illustratein vertical view, the operation of an embodiment of the invention;

FIG. 2 is a plan View of FIG. 1

FIGURES 3 and 4 illustrate the formation of the textile structure, and

FIGURES 5 and 6 illustrate, in a manner analogous to FIGURES 1 1 and 2,another embodiment.

According to the first embodiment, illustrated in FIG- URES 1 1 and 2,the yarns are divided into four sets, and precisely, two sets 11 and 12,which unwind from cones or loom beams ll and 12 (loom beams being shownin the drawing) and two sets 13 and 14 unwinding from cones 13 and 14'.Yarns 11 and 12 pass through two stationary combs 15 and 15', and yarns13 and 14 pass through movable combs 16 and 16. Said combs 16 and 16'have an alternating motion in the direction indicated by the arrows inFIG. 2, which is imparted thereto by actuating means schematicallyindicated as wheels and connecting rods '17 and 17, but which may be ofany structure, and said combs respectively engage groups of yarns l3 and14 to which they impart an alternating motion.

Yarn groups 11 and 12 which pass through combs 15 and 15' have astraight rectilinear motion. For this reason the yarns 11 and 12 will becalled warp yarns and the movable yarns 13 and 14 will be called weftyarns. Since the upper yarns 11 (with reference to FIG- URES 1 and 1 ofthe warp are displaced with respect to the lower yarns 12, and the Weftyarns 13- and 14 pass between the two groups, when all the yarns aregripped by the rolling mill 13 and 18', they are crushed so that theweft yarns become engaged as illustrated in FIGURES 3 and 4. Thecylinders 13* and 18' of the rolling mills rotate in the directionmarked by the arrows and advance the yarns at the desired speed. Theactuating means of cylinders 18, 18' may be of any nature and are notshown. The cylinders, besides pressing and drawing the yarns, also serveto apply an adhesive material by any suitable device, for instance bymeans of a trough 1-9 arranged below cylinder 18', which latter dipsinto the adhesive. The adhesive may be applied by means of cylinders 2iand 2 0, in all those cases in Which this is preferred to avoidincrustation of the cylinders 18, 18', especially when the combs areplaced very close to the cylinders, as it is normally preferable.

Because of the combination of the advancing motion due to cylinders 18,18 and the alternating motion due to the combs 16, 16, the two yarn sets13 and 14 become laid out on undulating paths, approximately shaped assinusoids, the amplitude and shape of Which depends on the amplitude ofthe stroke of the combs, the frequency of the alternating motion of thecombs and the peripheralspeed of the cylinders 18, 18. To cause theundulating paths of the yarns of the two sets to cross one another, thealternating motions of the combs are so controlled that their speeds areat any moment equal and opposite. As seen in FIGURES 1 and 1 the twocombs are arranged one above the other, or more exactly are displacedone with respect to the other in a direction which is perpendicular bothto the advancing direction of the yarns and to the direction of theiralternating motion.

Thereafter, the resulting structure is dried in an oven 23, which ispreferably rectilinear and may be a hot air, radiation, or dielectricloss oven, or an oven of different construction.

After drying, and while the fabric is still hot, it is preferablyenergically rolled, whereby the different sets of yarns are forcedpractically onto a single plane, with a resulting considerableimprovement in the strength of the bonding and in the appearance of thefabric. Rolling mill 24 is not described as it is a normal textilerolling mill, provided with one or more paper-coated cylinders,alternating with steel cylinders.

The temperatures of the cylinders of the rolling mill are between 100 C,and 110 C. if a rubber latex adhesive is used, and between 120 C. and140 C. if a synthetic resin adhesive is used. After passing through therolling mill, the textile material is wound on beams 26, 26 afterpassing through a reserve 25 which msures that there is the time to passfrom one to the other beam in winding up the material.

After the treatment hereinbefore described, the yarns are mutually setin their straight or undulating crossing paths and there is obtained atextile structure or nonwoven fabric, which is the object of theinvention, and is Well visible in FIG. 2. Theoretically, the four yarnsets lie on four different planes, but in practice, because of thepressure to which they have been subjected, they tend to bend the onearound the other, departing from these respective planes, and creatingalmost a weave between the various yarns which greatly increases theresistance of the textile structure.

To give a numerically precise example, one may employ two warps 11 and12 consisting each of five of spun viscose yarns 20/1 per cm. of width,and two wefts 13 and 14 consisting each of five spun viscose yarns 12/ 1per cm. of width. The advancing speed is 20 metres per minute. Thefrequency of the alternating motion of the combs is 460 periods perminute and the amplitude of this alternating motion is 4 centimetres.The total number of yarns is not specified because it is proportioned tothe width of the finished article. In the example above described,cylinders 13, 18' and 20, 20' are not heated.

The counts hereinbefore specified yield a structure having a goodstrength in both directions. However, if resistance in one direction,for instance, that of the warp, is most desired, the count of the yarnsin the other direction will be suitably decreased, and/ or their spacingwill be increased. As adhesive, a vinyl acetate resin in emulsion,plastified in a greater or lesser measure with butyl phthalate,according to the desired rigidity, is used. To obtain a stiff hand, apurer or lightly plastified resin (for instance with -15% of plastifieron the dry resin) is used, whereas a soft hand is obtained by using upto 50% of plastifier on the dry resin.

When the adhesion between the yarns is obtained by means of a liquidadhesive applied on cylinders 20, or

by any other means, there is no substantial difference in the treatmentwhen the type of adhesive is varied. The criteria which are set forthherein are applicable to any embodiment of the invention. In any casethe intensity of the squeezing action to which the article is submittedin the rolling mills must be regulated, and if the resins are absorbedwith difficulty by the yarns, wetting agents should be introduced in theadhesive bath, or the trough or the reservoirs containing the adhesiveshould be heated. Rubber latex (normally a pre-vulcanized latex) mayalso be used as adhesive; in that case, it would be useful to add caseinto stabilize the bath and possible also fillers (for example, calciumcarbonate). When rubber latex is used, it is preferable that the dryingtemperature should not exceed C. It is always possible to add to all theresins, as well as to the latex, colouring matter to obtain any desiredcolour of the fabric.

The dilution of the adhesive baths should be regulated in such a way asto provide a sufiicient amount of dry adhesive on the yarn to give aperfect bonding, while at the same time permitting the processingoperation to be carried out without incrusting the cylinders. When vinylacetate resins are used, the amount of dry resin should not exceed 3035%of the weight of the yarn, and with rubber latices it should not exceed45-50%.

. The two adhesive types mentioned hereinbefore are the mostcharacteristic. The first imparts to the fabric a stiff, semi-stiff orsoft hand (depending on the amount of plastifier used) with a slowelastic recovery. The second, on the contrary, provides an elasticfinishing with a resilient hand. More or less resilient hand may beobtained by suitable mixtures of vinyl acetate resins and rubber latex;in any case the pH of the vinyl acetate resins should be alkaline.

Vinyl acetate resins may be mixed with many other additives,stabilizers, fillers, waterproofing and creaseproofing agents (of theurea-formaldehyde or melamineformaldehyde type, and so on). There arepractically no limitations in the use of the various resins or adhesivesin general, and the equipment does not vary except in the cases in whichthe resin must be polymerized, or a natural or synthetic polymer must begelatinized or vulcanized. In those cases, after drying the liquidadhesive, a polymerization, gelatinization or vulcanization chamber willbe provided, and the chamber will have such a length and will be kept atsuch a temperature as a person skilled in the art may know to berequired forthe particular material used.

In more expensive articles, acrylic resins, which are employed similarlyto the vinyl acetate resins, have been found to be particularly usefulto obtain a brilliant finish, resistance to washing, stability andelasticity.

To carry out the aforementioned embodiment of the invention, practicallyany one of the yarns indicated in the general part of this descriptionmay be employed. Short fibre yarns, and particularly cotton and spunacetate, are particularly similar to spun viscose yarns, and thereforemay be processed without any variation of the example described. Othernatural and synthetic short fibre yarns may be processed in a likemanner. However, viscose rayon and other artificial and syntheticcontinuous filament yarns may also be used.

The following criteria, which are valid in general, are employed todetermine the advancing speed of the yarns, which is equal to the speedat which the non-woven fabric is manufactured and also to thetranslational speed of the warp.

The speed of manufacture of the article depends, from the mechanicalviewpoint, on the number of bends which it is desired to create and fromthe resistance of the yarn in view of the frequency of the alternatingmotion of the comb or combs. Experience has shown that the frequenciestolerated by the yarn in the alternating motion of the comb, aregenerally in the order of 600/800 strokes per minute. Higher frequenciesare possible with high strength yarns. Of course, with a given yarn, thegreater the amplitude of the stroke of the combs, and therefore theamplitude of the sinusoids, the smaller is the tolerable frequency. Letus suppose that it is desired to create 30 bends per linear metre at 700strokes per minute; in that case the advancing speed of the yarn will be700:30: 23.30 metres per minute. When such high speeds are adopted, itwill be suitable not to exaggerate in the eccentricity of the connectingrods which actuate the combs, which can be chosen in this case as 4 cms.

Always operating according to the diagrams of FIG- URES 1 and 2 it ispossible to process, in a second embodiment, yarns having a softeningpoint sufi'iciently low that they may be caused to adhere by softeningor incipient fusion through the application of pressure and heat. Suchyarns are those made of polyvinyl chloride or other vinyl polymers, suchas Saran (vinyl chloride-vinylidene chloride copolymer), vinyl acetateyarns and polyolephinic yarns, such as polyethylene and polypropylene.In this case an adhesive may be used or omitted.

If the adhesive is omitted, the cylinders 20 and 20' will be heated at atemperature sufiicient to soften the yarns and provoke their adhesion.On the contrary, if an adhesive is employed, this may be distributed oncylinders 20, 20 which, in that case, may also be heated, or may benon-heated, and the final bonding of the yarns is effected by therolling mill 24, which causes the yarns to soften and adhere the ones tothe others, and further causes the adhesive to harden and/or polymerize,if an adhesive has been used.

To give a numerically precise example, one may employ two warps of fiveyarns per cm. of width of spun polyvinyl chloride spun fibre having acount of 40/ 1, and two wefts of five yarns per cm. of width of the samepolyvinyl spun fibre having a count of 30/1. The advancing speed is 2.5metres per minute.

The frequency of the alternating motion of the combs is 600 periods perminute and its amplitude is 3 cms. It is possible to operate without anadhesive, imparting to cylinders 20, 20' a temperature of 120 C. toobtain an incipient softening of the yarns, and complete the bonding onthe rolling mill 24, the cylinders of which are heated to 130 C.

FIGURES 5 and 6 illustrate a further embodiment of the invention inwhich two wefts and a single warp are employed.

The wefts are indicated at 30 and 31 (the cones or beams from which theyunroll are omitted) and the warp at 32. Combs 33, 33 impart to the weftstheir alternating motion whereas the comb 32 guides said warp 32. Theadhesive is applied directly on heated cylinders 35, 35 by means ofreservoirs 36, 36 and spreaders 37, 37. The temporarily set textilestructure 38 passes between the rolling mill cylinders 39, 39, which arealso heated, and which transform it into the final structure 40.

To give a numerically precise example, one may employ for each weft anylon yarn having a count of 2/ 70,000 and in the number of 6 yarns percm. of width, and for the warp a like yarn having a count of 2/ 70,000in the number of 6 yarns per cm. of width. The advancing speed is 18-20metres per minute. The frequency of 6 the alternating motion of thecombs is 600 blows per minute, and its amplitude is 40 mm. If a rubberlatex adhesive is used, the temperature of cylinders 35, 35 is that ofthe ambient and that of cylinders 39, 39' is C.; if a synthetic resinadhesive is used, the said temperature becomes of 125-140 C.

The diagram of FIGURES 5 and 6 may also be carried into practice byusing any of yarns mentioned in the general part of this description.

Many variations may be carried out in the described operations. In placeof two or one group of warp yarns and two groups of weft yarns, a singlegroup of weft yarns, or more than two groups of weft yarns may be used.More than two groups of warp yarns may also be used. The application ofthe adhesive may be carried out directly on the yarns, or these may bepreviously impregnated with suitable adhesives. Any sheet materials maybe coupled with the textile structure by causing it to pass between therolling mill cylinders 20, 20 or in rolling mill 24, according to thecharacteristics of the sheet. The operations relating to the utilizationof the textile structure produced, such as for instance impregnation,may be carried out continuously without first winding up the non-wovenfabric. The thermal treatments and the application of pressure may berepeated or may take place in two or more phases. Other variations whichmay be effected by a person skilled in the art, are within the scope ofthe invention which has as its object a new and useful textile structureand a process for its manufacture.

What I claim is:

A web-like continuous textile structure comprising two sets of closelyspaced organic warp yarns running longitudinally throughout thestructure, a third set of similarly closely spaced organic weft yarnsinterposed between the two sets of the closely spaced warp yarns, eachyarn of the interposed weft set of yarns running in a sinusoidal mannerlongitudinally throughout the textile structure, each sinusoid lyinglaterally over a plurality of the longitudinally running warp yarns ofthe first two sets, the amplitude of the sinusoids being greater thanthe spacing between adjacent warp yarns and smaller than the Width ofthe textile structure, a fourth set of similarly closely spaced organicweft yarns interposed between the third set of sinusoidal weft yarns andone of the two sets of the longitudinally running warp yarns, saidfourth set of weft yarns running sinusoidal in alternate phaseopposition to the sinusoids of said third set of sinusoidal weft yarnsand across the sinusoids thereof, said warp yarns crushed upon the weftyarns and the weft yarns being bent to accommodate the warp yarns, andall of said yarns being bonded at their intersections with one another.

References Cited in the file of this patent UNITED STATES PATENTS2,500,690 Lannan Mar. 14, 1950 2,543,101 Francis Feb. 27, 1951 2,562,641Saunders July 31, 1951 2,704,734 Draper et a1 Mar. 22, 1955 2,738,298David et a1. Mar. 13, 1956

